خيارات البحث
النتائج 1781 - 1790 من 61,240
Soil and river contamination patterns of chlordecone in a tropical volcanic catchment in the French West Indies (Guadeloupe)
2016
Crabit A. | Cattan P. | Colin F. | Voltz M.
The aim of this study was to identify primary flow paths involved in the chlordecone (CLD) river contamination and quantify the CLD fluxes to assess CLD pollution levels and duration according to a typical catchment of the banana cropping area in the French Indies (Guadeloupe): the Pérou Catchment (12 km2) characterized by heavy rainfall (5686 mm year?1). Three sub-catchments (SC1, SC2 and SC3) were studied during the hydrological year 2009–2010: a pedological survey combined with a spatialized hydrochemical approach was conducted. The average soil concentration is higher in the Pérou Catchment (3400 ?g kg?1) than in the entire banana cropping area in Guadeloupe (2100 ?g kg?1). The results showed that CLD stocks in soils vary largely among soil types and farming systems: the weakest stocks are located upstream in SC1 (5 kg ha?1), where a majority of the area is non-cultivated; medium stocks are located in Nitisols downstream in SC3 (9 kg ha?1); and the greatest stocks are observed in SC2 on Andosols (12 kg ha?1) characterized by large farms. The annual water balance and the hydro-chemical analysis revealed that the three sub-catchments exhibited different behaviors. Pérou River contamination was high during low flows, which highlighted that contamination primarily originated from groundwater contributions. The results showed that only a small part of the catchment (SC2), contributing little to the water flow, comprises a major CLD contribution, which is in agreement with the highly contaminated andosol soils observed there. Another significant result considers that at least 50 years would be required to export the totality of the actual CLD soil stocks retained in the topsoil layer. The actual time for soil remediation will however be much longer considering (i) the necessary time for the chlordecone to percolate and be stored in the shallow aquifers and (ii) its travel time to reach the river. (Résumé d'auteur)
اظهر المزيد [+] اقل [-]Investigating filamentous slime growth downstream of a municipal discharge [Sacramento River, California].
1978
Salo J.E. | Ikesaki T.
Soil thresholds and a decision tool to manage food safety of crops grown in chlordecone polluted soil in the French West Indies
2017
Clostre F. | Letourmy P. | Lesueur Jannoyer M.
Due to the persistent pollution of soils by an organochlorine, chlordecone (CLD also known as Kepone ©) in the French West Indies, some crops may be contaminated beyond the European regulatory threshold, the maximum residue limit (MRL). Farmers need to be able to foresee the risk of not complying with the regulatory threshold in each field and for each crop, if not, farmers whose fields are contaminated would have to stop cultivating certain crops in the fields concerned. To help farmers make the right choices, we studied the relationship between contamination of the soil and contamination of crops. We showed that contamination of a crop by CLD depended on the crop concerned, the soil CLD content and the type of soil. We grouped crop products in three categories: (i) non-uptakers and low-uptakers, (ii) medium-uptakers, and (iii) high-uptakers, according to their level of contamination and the resulting risk of exceeding MRL. Using a simulation model, we computed the soil threshold required to ensure the risk of not complying with MRL was sufficiently low for each crop product and soil type. Threshold values ranged from 0.02 ?gkg?1 for dasheen grown in nitisol to 1.7 ?gkg?1 for yam grown in andosol in the high-uptake category, and from 1 ?gkg?1 for lettuce grown in nitisol to 45 ?gkg?1 for the leaves of spring onions grown in andosol in the medium-uptake category. Contamination of non-uptakers and low-uptakers did not depend on soil contamination. With these results, we built an easy-to-use decision support tool based on two soil thresholds (0.1 and 1 ?gkg?1) to enable growers to adapt their cropping system and hence to be able to continue farming. (Résumé d'auteur)tttttt
اظهر المزيد [+] اقل [-]The regulation of toxic air pollutants. A critical review.
1986
Cannon J.A.
An overview of hazardous/toxic waste incineration.
1986
Lee C.C. | Huffman G.L. | Oberacker D.A.
A review of recent reports dealing with the greenhouse effect of atmospheric carbon dioxide.
1984
Idso S.B.
Validation of the industrial source complex dispersion model in a rural setting [Air pollution].
1984
Heron T.M. | Kelly J.F. | Haataja P.G.
Assessing impacts of ozone on agricultural crops. II. Crop yield functions and alternative exposure statistics [Barley, beans, cotton, peanuts, sorghum, soybeans, tomato, wheat].
1984
Heck W.W. | Cure W.W. | Rawlings J.O. | Zaragoza L.J. | Heagle A.S. | Heggestad H.E. | Kohut R.J. | Kress L.W. | Temple P.J.
An update on college and university programs in air pollution control [USA].
1983
Cota H.M.
Sulfate levels in the southwest during the 1980 copper smelter strike [Arizona, New Mexico, and northwestern Texas, Air pollution].
1983
Eldred R.A. | Ashbaugh L.L. | Cahill T.A. | Flocchini R.G. | Pitchford M.L.
